Azothiophenes and mixtures thereof

ABSTRACT

Azothiophene disperse dyes of Formula (1) ##STR1## in which R, R 1 , R 2  and R 3  each independently is alkyl or alkenyl and mixtures thereof with other dyes are useful for dyeing synthetic textile material or a fiber blend thereof such as secondary cellulose acetate, cellulose triacetate, polyamide, polyacrylonitrile and aromatic polyester.

This application is a 371 of PCT/GB96/01533 filed Jun. 26, 1996.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to azothiophenes, to mixtures thereof with other dyes and to a process for the coloration of synthetic textile materials with azothiophenes and said mixtures.

SUMMARY OF THE INVENTION

The present azothiophenes are not specifically disclosed but fall within the same general class of azothiophene dyes described in UK Patent 1394365 and further similar dyes are disclosed in EP 588489. The present azothiophenes have advantages in terms of light fastness, pH stability and strength over dyes disclosed in UK Patent 1394365 and EP588489.

According to the present invention, there is provided an azothiophene of Formula (1): ##STR2## in which R, R¹, R² and R³ each independently is alkyl or alkenyl.

The alkyl groups represented by R, R¹, R² and R³ are preferably C₁₋₁₂ -alkyl, more preferably C₁₋₆ -alkyl and especially C₁₋₄ -alkyl. Those alkyl groups represented by R, R¹, R² and R³ which have three or more carbon atoms may be straight or branched chain alkyl groups. The alkenyl groups represented by R, R¹, R² and R³ are preferably C₂₋₁₂ -alkenyl, more preferably C₂₋₆ -alkenyl and especially C₂₋₃ -alkenyl. Preferred azothiophene dyes of Formula (1) are those in which R¹ and R² each independently is C₁₋₄ -alkyl or C₂₋₃ -alkenyl and R and R³ each independently is C₁₋₄ -alkyl. An especially preferred azothiophene of Formula (1) is that in which R¹ and R² are both ethyl and R and R³ are both methyl.

DETAILED DESCRIPTION OF THE INVENTION

The dyes of Formula (1) may be prepared by diazotising a 2-aminothiophene of Formula (2): ##STR3## and coupling the resulting diazo compound with an aromatic amine of Formula (3): ##STR4## in which R, R¹, R² and R³ are as hereinbefore defined. The diazotisation and coupling may be performed by conventionally used methods and the azothiophenes may be isolated using known techniques.

The azothiophenes of the present invention exist in various crystalline modifications and it is intended that the present definition of the azothiophenes includes such crystalline modifications which may be formed by established treatments such as heat treatment, solvent treatment, recrystallisation or seeding.

According to a further feature of the present invention, there is provided a mixture of dyes comprising an azothiophene of Formula (1) and an azothiophene of Formula (4): ##STR5## in which R⁴ is --CN, --Cl, --Br, --NO₂, C₁₋₄ -alkylcarbonyl, phenylcarbonyl, C₁₋₄ -alkylsulphonyl, --COC₁₋₄ -alkyl, --CONH₂, --CONH(C₁₋₄ -alkyl) or --CON(C₁₋₄ -alkyl)₂ ;

R⁵ is --H, C₁₋₄ -alkyl, phenyl or --COC₁₋₄ -alkyl;

R⁶ is --H, C₁₋₄ -alkyl, phenyl, NO₂, --CN, --Cl, --Br, --COC₁₋₄ -alkyl, --CONH₂, --CONH(C₁₋₄ -alkyl) or --CON(C₁₋₄ -alkyl)₂ ;

R⁷ is --H, C₁₋₄ -alkyl, C₁₋₄ -alkoxy, --Cl, --Br, --NHCOC₁₋₄ -alkyl or --NHSO₂ C₁₋₄ -alkyl;

R⁸ is --H, C₁₋₄ -alkyl or C₁₋₄ -alkoxy; and

R⁹ and R¹⁰ each independently is --H, C₁₋₄ -alkyl, C₂₋₄ -alkenyl or C₁₋₄ -alkyl substituted by --OH, C₁₋₄ -alkoxy, --CN, phenyl, C₁₋₄ -alkylCO--, C₁₋₄ -alkoxyCO--, HOC₁₋₄ -alkoxy, C₁₋₄ -alkoxy-C₁₋₄ -alkoxy, C₁₋₄ -alkoxy-C₁₋₄ -alkoxyCO--, --Cl or C₁₋₄ -alkoxyCOO.

Preferred dyes of Formula (4) are those in which R⁴ is --NO₂, --CN or C₁₋₄ -alkylcarbonyl, R⁵ is --H or C₁₋₄ -alkyl, R⁶ is --NO₂ or --CN, R⁷ is C₁₋₄ -alkyl or --NHCOC₁₋₄ -alkyl, R⁸ is --H or C₁₋₄ -alkoxy, R⁹ and R¹⁰ each independently is C₁₋₄ -alkyl. Especially preferred dyes of Formula (4) are those in which R⁴ is --NO₂, R⁵ is --H, R⁶ is --NO₂, R⁷ is --CH₃, --C₂ H₅, --NHCOCH₃, --NHCOC₂ H₅, --NHCOC₃ H₇ or --NHCOCH(CH₃)₃, R⁸ is --H or --OCH₃ and R⁹ and R¹⁰ are both --C₂ H₅.

The dye mixtures may be prepared as physical mixtures, by co-crystallisation or co-synthesis.

Mixtures of dyes of Formulae (1) and (4) preferably comprise, on a weight basis, from 5% to 95% of a dye of Formula (1), and from 95% to 5% of a dye of Formula (4), more preferably from 20% to 80% of a dye of Formula (1) and from 80% to 20% of a dye of Formula (4) and especially from 30% to 70% of a dye of Formula (1) and from 70% to 30% of a dye of Formula (4). Other useful mixtures contain from 65% to 75% of a dye of formula (1) and from 35% to 25% of a dye of Formula (4).

According to a further feature of the present invention, there is provided a mixture of dyes comprising an azothiophene of Formula (1) and an azo compound of Formula (5): ##STR6## in which R¹¹, R¹² and R¹³ each independently is --CN, --NO₂, --Cl or --Br,

R¹⁴ is --H, C₁₋₄ -alkyl, --Cl, --Br, --NHCOC₁₋₄ -alkyl or --NHSO₂ C₁₋₄ -alkyl;

R¹⁵ --H, C₁₋₄ -alkyl or C₁₋₄ -alkoxy; and

R⁹ and R¹⁰ are as herein before defined.

A first preferred dye of Formula (5) is that in which R¹¹ and R¹³ are --CN, R¹² is --NO₂, R¹⁴ is --CH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅.

A second preferred dye of Formula (5) is that in which R¹¹ is --CN, R¹² is --NO₂, R¹³ is --Br, R¹⁴ is --NHCOCH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅.

A third preferred dye of Formula (5) is that in which R¹¹ is --CN, R¹² is --NO₂, R¹³ is --Br, R¹⁴ is --NHCOC₂ H₅, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅.

A fourth preferred dye of Formula (5) is that in which R¹¹ and R¹³ are --CN, R¹² is --NO₂, R¹⁴ is --NHCOCH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅.

A fifth preferred dye of Formula (5) is that in which R¹¹ and R¹² are --NO₂, R¹³ is --CN, R.sup.¹⁴ is --NHCOCH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅.

A sixth preferred dye of Formula (5) is that in which R¹¹ and R¹² are --NO₂, R¹³ is --Br, R¹⁴ is --NHCOCH₃, R¹⁵ is --OCH₃ and R⁹ and R¹⁰ are both --C₂ H₅.

Mixtures of dyes of Formula (1) and (5) preferably comprise from 5% to 95% by weight of a dye of Formula (1) and from 95% to 5% by weight of a dye of Formula (5).

A first preferred mixture of dyes comprises from 10% to 20% of a dye of Formula (1) in which R¹ and R² each independently is C₁₋₄ -alkyl or C₂₋₃ -alkenyl and R and R³ each independently is C₁₋₄ -alkyl and from 90% to 80% of a dye of Formula (5) in which R¹¹ is --CN, R¹² is --NO₂, R¹³ is --Br, R¹⁴ is --NHCOCH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅.

A second preferred mixture of dyes comprises from 35% to 45% of a dye of Formula (1) in which R¹ and R² each independently is C₁₋₄ -alkyl or C₂₋₃ -alkenyl and R and R³ each independently is C₁₋₄ -alkyl and from 65% to 55% of a dye of Formula (5) in which R¹¹ and R¹³ are --CN, R¹² is --NO₂, R¹⁴ is --CH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅.

The azothiophene dyes of Formula (1) may advantageously be mixed with other known disperse dyes. As examples of such dyes, there may be mentioned the following dyes or classes of dyes.

One class of disperse dyes which may be mixed with the dyes of Formula (1) comprises azothiophene dyes derived from 2-amino-4-chloro-5-formylthiophene diazo components, for example dyes of the general formula: ##STR7## wherein E represents the residue of a coupling component. Such dyes are described in EP-A-0201896 and include, for example, the dye of the formula: ##STR8##

Another class of disperse dyes which may be mixed with the dyes of Formula (1) comprises azo dyes derived from nitro-substituted aminothiazole diazo compounds, for example dyes of the formula: ##STR9## wherein E represents the residue of a coupling component. As examples of such dyes, there may be mentioned the dyes of the formula: ##STR10##

Another class of disperse dyes which may be mixed with the dyes of Formula (1) comprises azo dyes derived from 3-amino-2,1-benzisothiazole diazo components, for example the dye of the formula: ##STR11##

Further dyes which may be mixed with the dyes of Formula (1) include the anthraquinone dyes of the formulae: ##STR12##

Another class of disperse dyes which may be mixed with the dyes of Formula (1) comprises dicyanovinylpyrroline dyes of the type described in WO94/10248 and GB-A-2191498. As an example of such dyes, there may be mentioned the dye of the formula: ##STR13##

Another class of disperse dyes which may be mixed with the dyes of Formula (1) comprises the 3-dicyanomethylidene-2,3-dihydrothiophen-1,1-dioxide derivatives of the type described in GB-A-2026528. As an example of such dyes, there may be mentioned the dye of the formula: ##STR14##

Another class of disperse dyes which may be mixed with the dyes of Formula (1) comprises yellow monoazo dyes obtained by the use of a hydroxypyridone coupling component, for example a 1,4-dialkyl-3-cyano-6-hydroxypyrid-2-one coupling component. Examples of such dyes include the dyes of the formula: ##STR15##

The disperse dyes of Formulae (6) to (18) may be mixed with dyes of Formula (1) in amounts of from 5-95% by weight of the former to from 95-5% by weight of the latter.

The azothiophenes and the mixtures thereof of the present invention are useful as disperse dyes and are valuable for colouring synthetic textile materials and fibre blends thereof.

According to a further feature of the present invention, there is provided a process for colouring a synthetic textile material or fibre blend thereof which comprises applying to the synthetic textile material an azothiophene of Formula (1) or a mixture thereof with at is least one other disperse dye.

The synthetic textile material may be selected from secondary cellulose acetate, cellulose triacetate, polyamide, polyacrylonitrile and aromatic polyester. The synthetic textile material is preferably polyamide such as polyhexamethylene adipamide or aromatic polyester especially polyethylene terephthalate. Fibre blends may comprise mixtures of different synthetic textile materials or mixtures of synthetic and natural textile materials. Preferred fibre blends include those of polyester-cellulose such as polyester-cotton. The textile materials or blends thereof may be in the form of filaments, loose fibres, yam or woven or knitted fibres.

The azothiophene of Formula (1) or mixtures thereof optionally in conjunction with other disperse dyes may be applied to the synthetic textile materials or fibre blends thereto by processes which are conventionally employed in applying disperse dyes to such materials and fibre blends.

Suitable process conditions may be selected from the following:

i) exhaust dyeing at a pH of from 4 to 6.5, at a temperature of from 125° C. to 140° C. for from 10 to 120 minutes and under a pressure of from 1 to 2 bar, a sequestrant optionally being added;

ii) continuous dyeing at a pH of from 4 to 6.5, at a temperature of from 190° C. to 225° C. for from 15 seconds to 5 minutes, a migration inhibitor optionally being added;

iii) printing direct at a pH of from 4 to 6.5, at a temperature of from 160° C. to 185° C. for from 4 to 15 minutes for high temperature steaming, or at a temperature of from 190° C. to 225° C. for from 15 seconds to 5 minutes for bake fixation with dry heat or at a temperature of from 120° C. to 140° C. and 1 to 2 bar for from 10 to 45 minutes for pressure steaming, wetting agents and thickeners (such as alginates) of from 5 to 100% by weight of the dye optionally being added;

iv) discharge printing (by padding the dye on to the textile material, drying and overprinting) at a pH of from 4 to 6.5, migration inhibitors and thickeners optionally being added;

v) carrier dyeing at a pH of from 4 to 6.5, at a temperature of from 95° C. to 100° C. using a carrier such as methylnaphthalene, diphenylamine or 2-phenylphenol, sequestrants optionally being added; and

vi) atmospheric dyeing of acetate, triacetate and nylon at a pH of from 4 to 6.5, at a temperature of 85° C. for acetate or at a temperature of 90° C. for triacetate and nylon for from 15 to 90 minutes, sequestrants optionally being added.

In all the above processes, the azothiophene of Formula (1) or mixture thereof is applied as a dispersion comprising from 0.001% to 4% of the azothiophene or mixture thereof in aqueous medium.

Compositions comprising dispersions of the azothiophene of Formula (1) or of mixtures of dyes or Formula (1) and the other disperse dyes mentioned above form further features of the present invention. The compositions typically comprise from 1% to 40% of the azothiophene of Formula (1) or mixture of dyes in an aqueous medium. The compositions are preferably buffered at pH 2 to 7 more preferably at pH 4 to 6.

These dye dispersions may further comprise ingredients conventionally used in coloration applications such as dispersing agents, for example lignosulphonates, naphthalene sulphonic acidformaldehyde condensates or pheno/creso/sulphanilic acid/formaldehyde condensates, surfactants, wetting agents such as alkyl aryl ethoxylates which may be sulphonated or phosphated, inorganic salts, de-foamers such as mineral oil or nonanol, organic liquids and buffers. Dispersing agents may be present at from 10% to 200% on the weight of the azothiophene of Formula (1) or on the weight of mixtures thereof. Wetting agents may be used at from 0% to 20% on the weight of the azothiophene of Formula (1) or on the mixture of dyes.

The dispersions may be prepared by bead milling the azothiophene of Formula (1) or mixture of dyes with glass beads or sand in an aqueous medium. Dispersions may have further additions of dispersing agents, fillers and other surfactants and may be dried, by a technique such as spray drying, to give a solid composition comprising from 5% to 60% of dyestuff.

In addition to the above-mentioned application processes, the azothiophenes of Formula (1) and dye mixtures derived therefrom may be applied to synthetic textile materials and fibre blends by ink-jet printing, the substrates optionally having been pretreated to aid printing. For ink-jet applications, the application medium may comprise water and a water-soluble organic solvent, preferably in a weight ratio of 1:99 to 99:1, more preferably 1:95 to 50:50 and especially in the range 10:90 to 40:60. The water-soluble organic solvent preferably comprises a C₁ -C₄ -alkanol, especially methanol or ethanol, a ketone, especially acetone, methyl ethyl ketone, 2-pyrrolidone or N-methylpyrrolidone, a glycol, especially ethylene glycol, propylene glycol, trimethylene glycol, butane-2,3-diol, thiodiglycol or diethylene glycol, a glycol ether, especially ethylene glycol monomethyl ether, propylene glycol monomethyl ether or diethylene glycol monomethyl ether, urea, a sulphone, especially bis-(2-hydroxyethyl) sulphone or mixtures thereof.

The azothiophenes of Formula (1) and dye mixtures derived therefrom may also be applied to textile materials using supercritical fluid solvents for example supercritical carbon dioxide, in which case the dye formulating agents may optionally be omitted.

The invention is further illustrated by the following Examples:

EXAMPLE 1

Preparation of: ##STR16##

Sodium nitrite (3.22g) was added to concentrated sulphuric acid (20 cm³) and the mixture heated to 70° C. and then cooled to 5° C. Further concentrated sulphuric acid (15 cm³) was added followed by 25 cm³ of a 86:14 mixture of acetic acid and propionic acid. 2-Amino-3-acetyl-5-nitrthiophene (8.5 g) was then added slowly below 0° C and the mixture stirred at -2° C. to 0° C. for 2 hours and then 0° C. to 2° C. for 3 hours when diazotisation was complete. The solution was then added to a mixture of 3-N,N-diethylaminoacetanilide (10.3 g), methanol (75 cm³), crushed ice (180 g) and sulphamic acid (1.0 g). The temperature was maintained at 0-5° C. and the pH at 1-2 by the addition of sodium acetate solution. The mixture was stirred at 0-5° C. for 2 hours and then the product was isolated by filtration and washed with water. Yield after drying 12.9 g.

When applied to an aromatic polyester material from an aqueous dispersion, it gives bright greenish-blue shades.

Comparative Data

The application properties of the dye of Example 1 were compared with those of a dye of Formula (6): ##STR17## which is disclosed in EP 588 489 as Example 2. a) by application on polyester dyed at 130° C. for 1 hour the dye of Formula (1) is at least twice as strong as the dye of Formula (6).

b) In a light fastness test (ISO 105:BO2) the light fastness of the dye of Formula (1) is better, having a fastness rating of 4-5 at both pale and heavy depths of shade, than the dye of Formula (6) having a fastness rating of 4.

c) the dyes of Formula (1) and Formula (6) were used to dye polyester at pale and heavy depths of shade at 130° C. for 1 hour at pH 4.5, 5.5, 6.5 and 7.5. The strength of the dyeings at each pH were assessed using reflectance colour difference measurements and are summarised in Table 1:

    ______________________________________                                                      Strength of Dyeing                                                Dye     Depth of Shade                                                                            pH 4.5  pH 5.5 pH 6.5                                                                               pH 7.5                                 ______________________________________                                         Example 1                                                                              Pale       100     100    100   98.7                                     Formula 6 Pale 100 100 83.3 43.3                                               Example 1 Heavy 100 100 100 100                                                Formula 6 Heavy 100 100 88.3 50.0                                            ______________________________________                                    

The following dyes of Formula (1) can be prepared by the procedure of Example 1, by diazotising the appropriate amine and coupling onto the appropriate coupling component.

    ______________________________________                                         Example   R         R.sup.1   R.sup.2 R.sup.3                                  ______________________________________                                           2 --CH.sub.3 --C.sub.3 H.sub.7 --C.sub.3 H.sub.7 --CH.sub.3                    3 --C.sub.2 H.sub.5 --C.sub.2 H.sub.5 --C.sub.2 H.sub.5 --CH.sub.3                                                  4 --CH.sub.3 --C.sub.2 H.sub.5                                                --C.sub.2 H.sub.5 --C.sub.2              ______________________________________                                                                               H.sub.5                             

The dyes of Formula (1) can be used in mixtures with other dyes, as shown in the following Examples, for the coloration of aromatic polyester textile material.

EXAMPLES 5-23

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR18##                                                                     Example          % A         % B                                               ______________________________________                                         5                5           95                                                  6 10 90                                                                        7 15 85                                                                        8 20 80                                                                        9 25 75                                                                        10 30 70                                                                       11 35 65                                                                       12 40 60                                                                       13 45 55                                                                       14 50 50                                                                       15 55 45                                                                       16 60 40                                                                       17 65 35                                                                       18 70 30                                                                       19 75 25                                                                       20 80 20                                                                       21 85 15                                                                       22 90 10                                                                       23 95 5                                                                      ______________________________________                                    

EXAMPLES 24-42

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR19##                                                                     Example          % A         % B                                               ______________________________________                                         24               5           95                                                  25 10 90                                                                       26 15 85                                                                       27 20 80                                                                       28 25 75                                                                       29 30 70                                                                       30 35 65                                                                       31 40 60                                                                       32 45 55                                                                       33 50 50                                                                       34 55 45                                                                       35 60 40                                                                       36 65 35                                                                       37 70 30                                                                       38 75 25                                                                       39 80 20                                                                       40 85 15                                                                       41 90 10                                                                       42 95 5                                                                      ______________________________________                                    

EXAMPLES 43-61

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR20##                                                                     Example          % A         % B                                               ______________________________________                                         43               5           95                                                  44 10 90                                                                       45 15 85                                                                       46 20 80                                                                       47 25 75                                                                       48 30 70                                                                       49 35 65                                                                       50 40 60                                                                       51 45 55                                                                       52 50 50                                                                       53 55 45                                                                       54 60 40                                                                       55 65 35                                                                       56 70 30                                                                       57 75 25                                                                       58 80 20                                                                       59 85 15                                                                       60 90 10                                                                       61 95 5                                                                      ______________________________________                                    

EXAMPLES 62-80

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR21##                                                                     Example          % A         % B                                               ______________________________________                                         62               5           95                                                  63 10 90                                                                       64 15 85                                                                       65 20 80                                                                       66 25 75                                                                       67 30 70                                                                       68 35 65                                                                       69 40 60                                                                       70 45 55                                                                       71 50 50                                                                       72 55 45                                                                       73 60 40                                                                       74 65 35                                                                       75 70 30                                                                       76 75 25                                                                       77 80 20                                                                       78 85 15                                                                       79 90 10                                                                       80 95 5                                                                      ______________________________________                                    

EXAMPLES 81-99

Dye A is the dye of Example 1

Dye B has the structure:

    ______________________________________                                           #STR22##                                                                     Example          % A         % B                                               ______________________________________                                         81               5           95                                                  82 10 90                                                                       83 15 85                                                                       84 20 80                                                                       85 25 75                                                                       86 30 70                                                                       87 35 65                                                                       88 40 60                                                                       89 45 55                                                                       90 50 50                                                                       91 55 45                                                                       92 60 40                                                                       93 65 35                                                                       94 70 30                                                                       95 75 25                                                                       96 80 20                                                                       97 85 15                                                                       98 90 10                                                                       99 95 5                                                                      ______________________________________                                    

EXAMPLES 100-118

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR23##                                                                     Example          % A         % B                                               ______________________________________                                         100              5           95                                                  101 10 90                                                                      102 15 85                                                                      103 20 80                                                                      104 25 75                                                                      105 30 70                                                                      106 35 65                                                                      107 40 60                                                                      108 45 55                                                                      109 50 50                                                                      110 55 45                                                                      111 60 40                                                                      112 65 35                                                                      113 70 30                                                                      114 75 25                                                                      115 80 20                                                                      116 85 15                                                                      117 90 10                                                                      118 95 5                                                                     ______________________________________                                    

EXAMPLES 119-137

Dye A is the dye of Example 1.

Dye B has the structure

    ______________________________________                                           #STR24##                                                                     Example          % A         % B                                               ______________________________________                                         119              5           95                                                  120 10 90                                                                      121 15 85                                                                      122 20 80                                                                      123 25 75                                                                      124 30 70                                                                      125 35 65                                                                      126 40 60                                                                      127 45 55                                                                      128 50 50                                                                      129 55 45                                                                      130 60 40                                                                      131 65 35                                                                      132 70 30                                                                      133 75 25                                                                      134 80 20                                                                      135 85 15                                                                      136 90 10                                                                      137 95 5                                                                     ______________________________________                                    

EXAMPLES 138-156

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR25##                                                                     Example          % A         % B                                               ______________________________________                                         138              5           95                                                  139 10 90                                                                      140 15 85                                                                      141 20 80                                                                      142 25 75                                                                      143 30 70                                                                      144 35 65                                                                      145 40 60                                                                      146 45 55                                                                      147 50 50                                                                      148 55 45                                                                      149 60 40                                                                      150 65 35                                                                      151 70 30                                                                      152 75 25                                                                      153 80 20                                                                      154 85 15                                                                      155 90 10                                                                      156 95 5                                                                     ______________________________________                                    

EXAMPLES 157-175

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR26##                                                                     Example          % A         % B                                               ______________________________________                                         157              5           95                                                  158 10 90                                                                      159 15 85                                                                      160 20 80                                                                      161 25 75                                                                      162 30 70                                                                      163 35 65                                                                      164 40 60                                                                      165 45 55                                                                      166 50 50                                                                      167 55 45                                                                      168 60 40                                                                      169 65 35                                                                      170 70 30                                                                      171 75 25                                                                      172 80 20                                                                      173 85 15                                                                      174 90 10                                                                      175 95 5                                                                     ______________________________________                                    

EXAMPLES 176-194

Dye A is the dye of Example 1

Dye B has the structure:

    ______________________________________                                           #STR27##                                                                     Example          % A         % B                                               ______________________________________                                         176              5           95                                                  177 10 90                                                                      178 15 85                                                                      179 20 80                                                                      180 25 75                                                                      181 30 70                                                                      182 35 65                                                                      183 40 60                                                                      184 45 55                                                                      185 50 50                                                                      186 55 45                                                                      187 60 40                                                                      188 65 35                                                                      189 70 30                                                                      190 75 25                                                                      191 80 20                                                                      192 85 15                                                                      193 90 10                                                                      194 95 5                                                                     ______________________________________                                    

EXAMPLES 195-213

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR28##                                                                     Example          % A         % B                                               ______________________________________                                         195              5           95                                                  196 10 90                                                                      197 15 85                                                                      198 20 80                                                                      199 25 75                                                                      200 30 70                                                                      201 35 65                                                                      202 40 60                                                                      203 45 55                                                                      204 50 50                                                                      205 55 45                                                                      206 60 40                                                                      207 65 35                                                                      208 70 30                                                                      209 75 25                                                                      210 80 20                                                                      211 85 15                                                                      212 90 10                                                                      213 95 5                                                                     ______________________________________                                    

EXAMPLES 214-232

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR29##                                                                     Example          % A         % B                                               ______________________________________                                         214              5           95                                                  215 10 90                                                                      216 15 85                                                                      217 20 80                                                                      218 25 75                                                                      219 30 70                                                                      220 35 65                                                                      221 40 60                                                                      222 45 55                                                                      223 50 50                                                                      224 55 45                                                                      225 60 40                                                                      226 65 35                                                                      227 70 30                                                                      228 75 25                                                                      229 80 20                                                                      230 85 15                                                                      231 90 10                                                                      232 95 5                                                                     ______________________________________                                    

EXAMPLES 233--251

Dye A is the dye of Example 1.

Dye B has the structure:

    ______________________________________                                           #STR30##                                                                     Example          % A         % B                                               ______________________________________                                         233              5           95                                                  234 10 90                                                                      235 15 85                                                                      236 20 80                                                                      237 25 75                                                                      238 30 70                                                                      239 35 65                                                                      240 40 60                                                                      241 45 55                                                                      242 50 50                                                                      243 55 45                                                                      244 60 40                                                                      245 65 35                                                                      246 70 30                                                                      247 75 25                                                                      248 80 20                                                                      249 85 15                                                                      250 90 10                                                                      251 95 5                                                                     ______________________________________                                    

EXAMPLES 252-270

Dye A is the dye of Example 4.

Dye B has the structure:

    ______________________________________                                           #STR31##                                                                     Example          % A         % B                                               ______________________________________                                         252              5           95                                                  253 10 90                                                                      254 15 85                                                                      255 20 80                                                                      256 25 75                                                                      257 30 70                                                                      258 35 65                                                                      259 40 60                                                                      260 45 55                                                                      261 50 50                                                                      262 55 45                                                                      263 60 40                                                                      264 65 35                                                                      265 70 30                                                                      266 75 25                                                                      267 80 20                                                                      268 85 15                                                                      269 90 10                                                                      270 95 5                                                                     ______________________________________                                    

EXAMPLES 271-289

Dye A is the dye of Example 4.

Dye B has the structure:

    ______________________________________                                           #STR32##                                                                     Example          % A         % B                                               ______________________________________                                         271              5           95                                                  272 10 90                                                                      273 15 85                                                                      274 20 80                                                                      275 25 75                                                                      276 30 70                                                                      277 35 65                                                                      278 40 60                                                                      279 45 55                                                                      280 50 50                                                                      281 55 45                                                                      292 60 40                                                                      283 65 35                                                                      284 70 30                                                                      285 75 25                                                                      286 80 20                                                                      287 85 15                                                                      288 90 10                                                                      289 95 5                                                                     ______________________________________                                    

EXAMPLES 290-308

Dye A is the dye of Example 4.

Dye B has the structure:

    ______________________________________                                           #STR33##                                                                     Example          % A         % B                                               ______________________________________                                         290              5           95                                                  291 10 90                                                                      292 15 85                                                                      293 20 80                                                                      294 25 75                                                                      295 30 70                                                                      296 35 65                                                                      297 40 60                                                                      298 45 55                                                                      299 50 50                                                                      300 55 45                                                                      301 60 40                                                                      302 65 35                                                                      303 70 30                                                                      304 75 25                                                                      305 80 20                                                                      306 85 15                                                                      307 90 10                                                                      308 95 5                                                                     ______________________________________                                    

EXAMPLES 309-327

Dye A is the dye of Example 3.

Dye B has the structure:

    ______________________________________                                           #STR34##                                                                     Example          % A         % B                                               ______________________________________                                         309              5           95                                                  310 10 90                                                                      311 15 85                                                                      312 20 80                                                                      313 25 75                                                                      314 30 70                                                                      315 35 65                                                                      316 40 60                                                                      317 45 55                                                                      318 50 50                                                                      319 55 45                                                                      320 60 40                                                                      321 65 35                                                                      322 70 30                                                                      323 75 25                                                                      324 80 20                                                                      325 85 15                                                                      326 90 10                                                                      327 95 5                                                                     ______________________________________                                    

EXAMPLES 328-346

Dye A is the dye of Example 3.

Dye B has the structure:

    ______________________________________                                           #STR35##                                                                     Example          % A         % B                                               ______________________________________                                         328              5           95                                                  329 10 90                                                                      330 15 85                                                                      331 20 80                                                                      332 25 75                                                                      333 30 70                                                                      334 35 65                                                                      335 40 60                                                                      336 45 55                                                                      337 50 50                                                                      338 55 45                                                                      339 60 40                                                                      340 65 35                                                                      341 70 30                                                                      342 75 25                                                                      343 80 20                                                                      344 85 15                                                                      345 90 10                                                                      346 95 5                                                                     ______________________________________                                    

EXAMPLES 347-365

Dye A is the dye of Example 3

Dye B has the structure:

    ______________________________________                                           #STR36##                                                                     Example          % A         % B                                               ______________________________________                                         347              5           95                                                  348 10 90                                                                      349 15 85                                                                      350 20 80                                                                      351 25 75                                                                      352 30 70                                                                      353 35 65                                                                      354 40 60                                                                      355 45 55                                                                      356 50 50                                                                      357 55 45                                                                      358 60 40                                                                      359 65 35                                                                      360 70 30                                                                      361 75 25                                                                      362 80 20                                                                      363 85 15                                                                      364 90 10                                                                      365 95 5                                                                     ______________________________________                                     

I claim:
 1. An azothiophene of Formula (1): ##STR37## in which R, R¹, R² and R³ each independently is alkyl or alkenyl.
 2. An azothiophene according to claim 1 in which each of R, R¹, R² and R³ is C₁₋₄ -alkyl.
 3. An azothiophene according to claim 2 in which R¹ and R² are both ethyl and R and R³ are both methyl.
 4. A dye mixture comprising an azothiophene according to claim 1 and an azothiophene of Formula (4): ##STR38## in which R⁴ is --CN, --Cl, --Br, --NO₂, C₁₋₄ -alkylcarbonyl, phenylcarbonyl, C₁₋₄ -alkylsulphonyl, --COC₁₋₄ -alkyl, --CONH₂, --CONH(C₁₋₄ -alkyl) or --CON(C₁₋₄ -alkyl)₂ ;R⁵ is --H, C₁₋₄ -alkyl, phenyl or --COC₁₋₄ -alkyl; R⁶ is --H, C₁₋₄ -alkyl, phenyl, NO₂, --CN, --Cl, --Br, --COC₁₋₄ -alkyl, --CONH₂, --CONH(C₁₋₄ -alkyl) or --CON(C₁₋₄ -alkyl)₂ ; R⁷ is --H, C₁₋₄ -alkyl, C₁₋₄ -alkoxy, --Cl, --Br, --NHCOC₁₋₄ -alkyl or --NHSO₂ C₁₋₄ -alkyl; R⁸ is --H, C₁₋₄ -alkyl or C₁₋₄ -alkoxy; and R⁹ and R¹⁰ each independently is --H, C₁₋₄ -alkyl, C₂₋₄ -alkenyl or C₁₋₄ -alkyl substituted by --OH, C₁₋₄ -alkoxy, --CN, phenyl, C₁₋₄ -alkylCO--, C₁₋₄ -alkoxyCO--, HOC₁₋₄ -alkoxy, C₁₋₄ -alkoxy-C₁₋₄ -alkoxy, C₁₋₄ alkoxy-C₁₋₄ -alkoxyCO--, --Cl or C₁₋₄ -alkoxyCOO.
 5. A mixture according to claim 4 wherein the dye of Formula (4) has a structure in which R⁴ is --NO₂, R⁵ is --H, R⁶ is --NO₂, R⁷ is --CH₃, --C₂ H₅, --NHCOCH₃, --NHCOC₂ H₅, --NHCOC₃ H₇ or --NHCOCH(CH₃)₃, R⁸ is --H or --OCH₃ and R⁹ and R¹⁰ are both --C₂ H₅.
 6. A dye mixture comprising an azothiophene according to claim 1 and an azo compound of Formula (5): ##STR39## in which R¹¹, R¹² and R¹³ each independently is --CN, --NO₂, --Cl or --Br;R¹⁴ is --H, C₁₋₄ -alkyl, --Cl, --Br, --NHCOC₁₋₄ -alkyl or --NHSO₂ C₁₋₄ -alkyl; R¹⁵ is --H, C₁₋₄ -alkyl or C₁₋₄ -alkoxy; and R⁹ and R¹⁰ each independently is --H, C₁₋₄ -alkyl, C₂₋₄ -alkenyl or C₁₋₄ -alkyl substituted by --OH, C₁₋₄ -alkoxy, --CN, phenyl, C₁₋₄ -alkylCO--, C₁₋₄ -alkoxyCO--, HOC₁₋₄ -alkoxy, C₁₋₄ -alkoxy-C₁₋₄ -alkoxy, C₁₋₄ -alkoxy-C₁₋₄ -alkoxyCO--, --Cl or C₁₋₄ -alkoxyCOO.
 7. A mixture according to claim 6 wherein the dye of Formula (5) has one of the following structures:(a) wherein R¹¹ and R¹³ are --CN, R¹² is --NO₂, R¹⁴ is --CH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅, (b) wherein R¹¹ is --CN, R¹² is --NO₂, R¹³ is --Br, R¹⁴ is --NHCOCH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅. (c) wherein R¹¹ is --CN, R¹² is --NO₂, R¹³ is --Br, R¹⁴ is --NHCOC₂ H₅, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅. (d) wherein R¹¹ and R¹³ are --CN, R¹² is --NO₂, R¹⁴ is --NHCOCH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅. (e) wherein R¹¹ and R¹² are NO₂, R¹³ is --CN, R¹⁴ is --NHCOCH₃, R¹⁵ is --H and R⁹ and R¹⁰ are both --C₂ H₅. (f) wherein R¹¹ and R¹² are --NO₂, R¹³ is --Br, R¹⁴ is --NHCOCH₃, R¹⁵ is --OCH₃ and R⁹ and R¹⁰ are both --C₂ H₅.
 8. A dye mixture comprising an azothiophene according to claim 1 and a disperse dye having one of the following structures: ##STR40##
 9. A composition comprising a dispersion of an azothiophene according to claim 1 in an aqueous medium.
 10. A process for colouring a synthetic textile material or fibre blend thereof which comprises applying thereto an azothiophene according to claim
 1. 11. A process for colouring a synthetic textile material or fibre blend thereof which comprises applying thereto a dye mixture according to claim
 4. 